Page 7 - 3DF Zephyr

 Pixels size must be higher than 2 µm; therefore it is strongly recommended to exploit camera sensor bigger than 1/2.3" even if smaller sensors may be used depending on the accuracy you want to reach;  You'd better draw your attention to pixels size rather than pixels mount for each picture. For instance, if a 36 megapixel full-frame reflex (35.9 x 24 mm) is being employed it is worthwhile to shoot at a lower resolution than the maximum provided. That is the way to get bigger pixels in the images even though less; Lenses. Every survey has its own features and conditions so choosing the most suitable lens for that depends on both environment status (light, obstacles on field, user movement capability) and features of the survey subject/scene. Following a few tips are provided so as to pick the proper photographic gear:  Full-frame cameras: use lenses with focal length values between 25 and 50 mm;  Aps-c cameras or lower sensor size: use lenses with focal length values between 18 and 35 mm considering a crop factor value between 1.5 e 1.6; It is strongly recommended to shoot keeping the same focal length for all the pictures you take. Even if Zephyr can handle several kind of cameras and lenses at the same time and in the same project, you can get better and faster results if working with an equivalent set-up; Shooting techniques. Following some proposals for standard photographic acquisition are featured. At any rate survey modalities are different and need to be adapted on a case by case basis. Parallel axis capture That is exploited with planar or regular surface in application fields such as architecture and aerial photogrammetry. Red fills show the overlap area among the pictures taken. Convergent axis capture